A 21-year-old school aide was busted yesterday on charges of sexually harassing and endangering teenage girls at the Queens HS for Science, Schools Investigator Richard Condon said.

Nicholas Pichardo is accused of menacing actions against four girls that involved inappropriate touching and kissing as well as offensive verbal actions, including saying to one girl, “If I didn’t work here, would you f – – – me?”

Pichardo hit on girls in the girls’ locker room, asked them for dates and their phone numbers, and licked his lips in a suggestive manner, the investigation found.

Last spring, Condon’s office concluded that the allegations against Pichardo could be verified after interviews with students, faculty and administrators. The aide was fired and the case referred to the Queens district attorney’s office.

In an interview with schools investigators, Pichardo denied all the allegations. He claimed the students asked him to go on dates and that he rebuffed them.

He was charged with two misdemeanors: endangering the welfare of a child and sexual abuse in the third degree. The maximum penalty, if he is convicted, is 15 months imprisonment.